Transport Characteristics of Asymmetric Cellulose Triacetate Hemodialysis Membranes

Abstract

Aims: The objective of this study was to compare the transport characteristics of highly asymmetric cellulose triacetate (ATA™) membranes with that of both symmetric cellulose triacetate and asymmetric polysulfone membranes. Methods: Data were obtained for solute clearance and sieving coefficients of vitamin B12 and a range of polydisperse dextrans using ATA™ SOLACEA-25H and Optiflux F250NR polysulfone dialyzers. Results for these, and the CT190 symmetric cellulose triacetate dialyzer, were analyzed using available membrane transport models. Results: The ATA™ had the largest solute clearance, although the homogeneous CT190 dialyzer had the highest sieving coefficients. These differences were a direct result of the differences in the underlying membrane morphology, with the asymmetric ATA™ membrane providing much higher diffusive transport rates (and thus higher solute clearance). Conclusions: These results demonstrate the importance of membrane morphology on dialyzer transport and provide important insights into the effective clinical performance observed with the highly asymmetric ATA™ dialyzers.